Phloem, a vital vascular tissue in plants, consists of four main components: sieve tubes, companion cells, phloem parenchyma, and phloem fibers. These elements work together to transport sugars and other organic molecules throughout the plant.
Here’s a more detailed look at each component:
Sieve tubes:
These are long, continuous tubes formed by the end-to-end arrangement of sieve tube elements. They have perforated end walls called sieve plates, allowing for the flow of fluid between cells.
Companion cells:
These specialized cells are closely associated with sieve tube elements and help to support their function. They provide metabolic support and regulate the sugar transport process.
Phloem parenchyma:
These are living cells that store food and water, and they also help in the lateral conduction of nutrients.
Phloem fibers:
These are dead, elongated cells that provide mechanical support to the phloem tissue, making it strong and flexible.